electrolysis of brine

Question 1

What does electrolysis of brine produce

Answer 1

sodium hydroxide
hydrogen
chlorine

Question 2

Why is sodium hydroxide useful

Answer 2

Sodium hydroxide is used in food processing and removing pollutants during paper manufacture.

Question 3

Why is hydrogen useful

Answer 3

Hydrogen is used in the production of hydrochloric acid and as a fuel.

Question 4

Why is chlorine useful

Answer 4

Chlorine is a disinfectant and is also used in making plastics.

Question 5

What happens during the electrolysis of brine

Answer 5

A solution of NaCl(aq) produces chlorine, hydrogen and sodium hydroxide when electrolysed.

Question 6

how is chlorine produced from the electrolysis of brine

Answer 6

Chloride ions react at the positive electrode (anode), to form chlorine gas

chloride ions are removed from solution

sodium chloride is melted in water

chloride ions lose electrons so the reaction is oxidation

Question 7

What is the half equation for chlorine at the anode and is it oxidation or reduction

Answer 7

2Cl– → Cl2 + 2e–

reaction is oxidation

Question 8

how is hydrogen produced from the electrolysis of brine

Answer 8

hydrogen ions from the water, react at the negative electrode (cathode) to form hydrogen gas

hydrogen ions are removed from solution

sodium chloride is melted in water

Each hydrogen ion has gained an electron so the reaction is reduction

Question 9

What is the half equation for hydrogen at the cathode and is it oxidation or reduction

Answer 9

2H+(aq) + 2e− → H2(g)

reaction is reduction

Question 10

how is sodium hydroxide produced from the electrolysis of brine

Answer 10

hydroxide ions stay in solution forming sodium hydroxide solution, often referred to as caustic soda.

Question 11

is brine an aqueous solution or molten solution

Answer 11

aqueous solution